Modern manufacturing industry demands low cost and high efficient welding processes to remain competitiveness in the time of globalization. In this study, conventional gas metal arc welding (GMAW) was modified, a double-electrode GMAW (DE-GMAW) system is developed and DE-GMAW process is implemented through optimization of the design and process parameters and suitable selection of igniting sequence of double arcs. High speed welding tests were carried out to examine the effects of different factors on occurrence of weld formation defects. Through observing the weld bead appearance in DE-GMAW, the values of critical welding speed were determined under different levels of welding current and welding speed.